Genomic imprinting is defined as an epigenetic modification of a gene or the chromosome on which it resides that is present in the gamete or zygote and leads to differential expression of the two parental alleles of the gene in somatic cells of the offspring. It is a normal form of gene regulation that causes a bias in the expression of alleles inherited from each parent. Till date more than 70 imprinted genes have been identified from both mouse and humans. Imprinted genes show species specific, tissue specific and developmental stage specific imprinting.

The SLC22A18 is an imprinted gene that has a transcript size of 1.7-kb transcript with highest expression in liver, heart, and kidney. The open reading frame encodes a protein of 424 amino acids. The SLC22A18 gene consists of 11 exons spanning a genomic area of 23 kb. The gene encodes a predicted protein with multiple membrane-spanning segments that belongs to the polyspecific transporter/multidrug resistance gene family. The role of SLC22A18 in the development and progression of several human neoplasms like Wilm's tumor, rhabdomyosarcoma, breast cancer and lung cancer and its reduced expression in hepatoblastomas and hepatocarcinomas has been well documented.

 

The aim of this work was to

1. understand the regulation of SLC22A18 expression and it's imprinting mechanism.